pros and cons of smart pointers

Question

I came to know that smart pointer is used for resource management and supports RAII.

But what are the corner cases in which smart pointer doesn\'t seem smart and things

Answer 1

Watch out at the transitions - when assigning between raw and smart pointers. Bad smart pointers - like _com_ptr_t - make it worse by allowing implicit conversions. Most errors happen at the transition.

Watch out for cycles - as mentioned, you need weak pointers to break the cycles. However, in a complex graph that's not always easy to do.

Too much choice - most libraries offer different implementations with different advantages / drawbacks. Unfortunately, most of the time these different variants are not compatible, which becomes a probem when mixing libraries. (say, LibA uses LOKI, LibB uses boost). Having to plan ahead for enable_shared_from_this sucks, having to decide naming conventions between intrusive_ptr, shared_ptr and weak_ptr for a bunch of objects sucks.

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For me, the single most e advantage of shared_ptr (or one of similar functionality) is that it is coupled to its destruction policy at creation. Both C++ and Win32 offers so many ways of getting rid of things it's not even funny. Coupling at construction time (without affecting the actual type of the pointer) means I have both policies in one place.